| Mesoporous silica nanoparticles(SP) have attracted great attentions in the biologicalapplication of nanocarriers for their unique structure features, such as high total surface area,tunable pore diameter, narrow size distribution and good biocompatibility. In this thesis, SPwith different fuctional groups were prepared, and their application in controlled release ofanticancer drug and gene transfection were studied. The main contents and results of thiswork are as following:First, SP were fabricated by using CTAB as template and NaOH as catalyst, and theeffects of the CTAB and NaOH concentrations on the diameter and ΞΆ-potential of SP werediscussed. SP with an average diameter of about180nm was obtained at CTAB and NaOHconcentration of5.7mM and14mM, respectively. Amine-fucntionalized SP was prepared bypost-synthesis method, and then as-synthesized4-cyanopentanoic acid dithiobenzoate werelinked to their surface.Second, pH-responsive anticancer prodrugs were prepared by conjugating adriamcin(ADR) to SP through an acid-sensitive carboxylic hydrazone linker, and then adriamcinrelease profile in vitro from SP-ADR at different pH values were studied. CLSM resultindicated that SP-based ADR can be internalized by HeLa cells. Cytotoxicities of free ADRand SP-ADR were evaluated and compared using HeLa cells via MTT colorimetry.At last, PEG-modified PEI25k was coated on the surface of SP via an acid-sensitiveimine linker, and then the feasibility of this material used as carrier for gene transfection wasexplored. Cytotoxicity of this carrier were studied via MTT assays. Diameter andzeta-potential of SP-PEI-PEG/DNA with different weight ratio were determined by DLS. Thecapability of SP-PEI-PEG to condense DNA were evaluated by agarose gel electrophoresis.The results demonstrated that SP-PEI-PEG showed low cytotoxicity against HeLa cells andcould bind with plasmid DNA form stable SP-DNA complex at weight ratio of64, and thusprivided a promising carrier for gene transfection. |
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